I know for some people the summer holiday is a nightmare financially and logistically so not downplaying that. But for me... I'm mostly looking forward to them going back so that the house can be clean again! 
Between everyone being around the whole time and the fact that both DH and I have been juggling normal work AND kids' activities, we've barely kept on top of the bare minimum. Thank goodness we have fortnightly cleaners otherwise the place would be a health hazard.
Once they go back and I can get back into my routine of sweeping/tidying/vacuuming a floor each day, wiping down more than the basic surfaces, spotting and identifying where clutter is building up and discarding it as well as all the little tasks I only do occasionally but haven't been done at all over the holidays like delimescaling things and getting rid of the mould in the bit under the shower door!
Anyone else!?